fusion_list = [(1,5),(1.2,5),(3,8)]

pop_index = []
for m in range(len(fusion_list)):
    for n in range(m+1,len(fusion_list)):
        error_x = abs(fusion_list[m][0] - fusion_list[n][0])
        error_y = abs(fusion_list[m][1] - fusion_list[n][1])
        error = (error_x ** 2 + error_y ** 2) ** 0.5
        if error < 0.5:
            pop_index.append(m)
for j in range(len(pop_index)):
    del fusion_list[pop_index[j]]
print(fusion_list)